American Thoracic Society Documents 401 Figure 2. Algorithm forinitiating empiric antibi-otic therapy for hospital-acquired pneumonia (HAP),ventilator-associated pneu-monia (VAP), and health-care-associatedpneumonia(HCAP). Figure 2.
One milligram is one thousandth of a gram and one thousand micrograms. A milligram is generally abbreviated as mg. MICROGRAM. One microgram is one millionth of a gram and one thousandth of a milligram. It is usually abbreviated as mcg or ug. Mcg and ug are the same.
The number of micrograms in a milliliter of a substance is equal to the density of the substance expressed in micrograms per milliliter. A microgram measures mass, and a milliliter measures volume; they do not convert without the substance's density.